This invention relates to a method of manufacturing slide fastener stringers having a woven fabric tape carrying along its one longitudinal edge a row of continuous coupling elements which is formed into a spirally coiled structure and woven into the carrier tape in the course of the weaving of the latter.
In the method of manufacturing the slide fastener stringers just described, there have heretofore been used shuttle looms having a pair of shuttles, one of which serves to carry a weft yarn for forming the carrier tape fabric and the other of which carries a continuous filament for forming the coupling elements of coiled structure to be woven into the tape fabric. The shuttle carrying the element-forming filament is, during the tape weaving, reciprocally moved transversely in criss-cross relation to warp yarns for forming the tape fabric in order to enable the element-forming filament to interweave with a selected group of warp yarns during shedding of the latter which form the element-carrying edge. The element-forming filament loops over a mandrel wire located adjacent the warp yarns of the tape edge, which wire is arranged for the purpose of forming and retaining the configuration of the resulting coupling elements in the vicinity of the coupling heads. This is effected in such a manner that the filament-carrying shuttle is reciprocated alternately over and under the wire as the latter is lowered and raised in this order during the tape weaving operation. The filament-carrying shuttle known in the art has the drawback that the filament was let go twisted as it was spirally coiled to form a row of coupling elements. And, therefore, resulting coupling elements were liable to become distorted or deformed throughout the parts including a coupling head, legs and connecting portions, thereby causing a mal-functioning in the intermeshing engagement between the opposed rows of coupling elements.